CA1141965A - Production of agent for desulfurizing crude iron and steel melts - Google Patents
Production of agent for desulfurizing crude iron and steel meltsInfo
- Publication number
- CA1141965A CA1141965A CA000350242A CA350242A CA1141965A CA 1141965 A CA1141965 A CA 1141965A CA 000350242 A CA000350242 A CA 000350242A CA 350242 A CA350242 A CA 350242A CA 1141965 A CA1141965 A CA 1141965A
- Authority
- CA
- Canada
- Prior art keywords
- cao
- weight
- calcium oxide
- carbide
- block
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
- C21C1/025—Agents used for dephosphorising or desulfurising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
- C21C7/0645—Agents used for dephosphorising or desulfurising
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Coating With Molten Metal (AREA)
Abstract
PRODUCTION OF AGENT FOR DESULFURIZING CRUDE IRON AND STEEL MELTS
ABSTRACT OF THE DISCLOSURE
The invention relates to the production of an agent for desulfuriz-ing crude iron and steel melts, the desulfurizing agent being based on cal-cium carbide containing calcium carbide To this end, a calcium carbide/cal-cium oxcide/starting melt mixture with a CaO-content within the range 20 to 80 weight% is produced from lime and coke and allowed to solidify to a block.
While the solidified block still has an average temperature of more than 400 C, it is crushed to particulate material with a size of less than 150 mm.
Next, the hot crushed material of at least 400° C is admixed with a quantity of calcium oxide necessary to have in the resulting mixture an overall con tent of CaO corresponding to that desired for the final product. The whole is thoroughly mixed and crushed with exclusion of moisture at temperatures higher than 100° C to particulate material with a size of less than 10 milli-meter.
ABSTRACT OF THE DISCLOSURE
The invention relates to the production of an agent for desulfuriz-ing crude iron and steel melts, the desulfurizing agent being based on cal-cium carbide containing calcium carbide To this end, a calcium carbide/cal-cium oxcide/starting melt mixture with a CaO-content within the range 20 to 80 weight% is produced from lime and coke and allowed to solidify to a block.
While the solidified block still has an average temperature of more than 400 C, it is crushed to particulate material with a size of less than 150 mm.
Next, the hot crushed material of at least 400° C is admixed with a quantity of calcium oxide necessary to have in the resulting mixture an overall con tent of CaO corresponding to that desired for the final product. The whole is thoroughly mixed and crushed with exclusion of moisture at temperatures higher than 100° C to particulate material with a size of less than 10 milli-meter.
Description
The pre~0nt invention relates to a proce~s for making an agent for desul~urizing crude lron and steel melts, the desulfurizing agent being based on calcium carbide containing calcium oxide.
It is generally accepted that crude iron and steel melt~ can be desulfurized with the use of calcium carbide (briefly termed carbide hereinafter) containing calcium oxide ~brie~ly termed lime herein~
after); c~. German Patents 1 160 457 and 20 37 758 .
In preparing these desulfurizing agents, it has heretofore been customary to admix a liquid carbide melt with a quantity of fine particulate lime necessary to have a homogeneous mixture in the melt.
Next, the whole is allowed to cool, and crushed.
More specifically, it has heretofore been oustomary, to introduce fine particulate lime mto the jet of carbide tapped off from the furnaoe~ Despite the fact that a carbide melt can be admixed with a limited quan~ity of lime only and that liquid carbide is hazardous to handle, the method just described has long been held in the art to be irreplaceable~ Nore particularly, a CaC2/CaO-mixture prepared in the melt has long beer held to be ideally suitable for use in the desulf~rization o~ metal melts~
The preser.t ~nver,tion now unexpectedly provides a process for making a highly efficient agent for de-sulfurizing crude lron and steel melts, which avoids the adverse effects encountered with the methods described heretofore and which comprises: thermally producing, fm m lime and coke, a calcium carbide/cal-cium oxide/starting melt mixture with a CaO-content within the range 20 to 80 weight%; allowing the starting melt mixture to solidify to a block; allow-ing the solidified block to assume an average temperature of more than 400 C, preferably a temperature between 400 C and the solidification point of the ~elt, and precrushing it at that te~perature to particulate ~aterial with a size of less than 150 mm; admlxing the hot crushed material of at least 400 C with a quantity of CaO necessary to have in the resulting mix-ture an o~erall oontent of CaO corresponding to that desired for the finalpro~uct, preferably a CaO-content of more than 45 up to 90 weight%;
thoroughly mixing and crushing the whole with exclusion of moisture a~
temperatures higher than 100 C to particulate material with a size of less than 10 millimeter, preferably less than 10 mierons and ccoling the ground pulverulent material, with exclusion o moisture.
It is good praetiee to use as the caleium carbide/ealeium oxide/
starting melt mixture one which eontains 20 to 45 weight~ of CaO and has been prepared thermally in customary manner, f.rom lime and coke. It .is also possible, however, by admixing a calcium carbide melt ha~ing up to 45 weight% of calcium oxide therein with fine particulate calcium oxide so as to establish a CaC-content of up to 80 weigh~% initially to produoe a calcium carbide/calcium oxide starting melt mixture which is allowed to solidi~y to give a block and the latter is precrus~ed at temperatures higher than 400 C.
The pre~ent invention avoids the need to mix lime with a carbide melt and the di~iculties which are associated with this. Further technically beneficial e~fect~ reside in the following: the carbide melt can be produced without the need to use a specifically composed burden in each particular case or to grind lime to a given particle si~e. In3tead of this, u~e can be made in the present process of a carbide block of which the CaC2 :
CaO-ratio by weight may vary within very wide limi~s?
i. e. which may practically be selected at will; also, use can be made of coarse particulate material with a ~iæe of 8 to 60 mm, for example.
EXAMPLE 1:
A melt with a Cae2-content of 80 weight% and a CaO-content o~ 20 weight% as customarily used in the-prod~ction of comme~ial carbide was placed in a crucible and allowed to cool therein to a carbide block o~ analogous composition.
Once the block was found to have cooled down to an average temperature o~ about 600 C, it was precrushed to particulate material with a ~7e o~ less than 150 mm.
Next~ the hot carbide of 500 C was covered with a quantity o~ lime (in the ~orm of partlcles with a si7-e of 8 to 60 mm) necessary to obtain a mixture wi~h an overall CaO-conten~
o~ 50 wei~h~g6.
Next, the mix*ure was ground at 100 C with exclusion ~ 6 5 of moisture to particles with a size of up to 100 microns and the ground product was cooled to room temperature, with exclusion of moisture.
1500 kg of the product so made was used for de-sulfurizing 300 000 kg of a crude iron melt in customarymanner~ of which the sulfur content initially o~ 0.03 weight% was reduced down to le~s than 0.005 weight%.
EXAMPLE 2:
Calci~ carbide wa~ produced thermally in customary manner, from lime and coke. The furnace burden contained the lime/coke-mix~ure in a ratio by weight of about 110 : 40. This corresponded to carbide containing about 45 weight% of CaO.
Introduced into the jet o~ liquid carbide tapped of~ was CaO int the ~orm of parti.cles with a size o~ 3 to 8 mm, which was used in a qua~Ltity necessary to have an average CaO-colltent of about 80 weight% in the crucible (about 1.2 to 1.3 metric tons o~ C~O per ton o~ material tapped of~).
The material in the crucible was allowed to cool down to an average temperature of not les~ than 600 C
which was the case a~ter 4 hour~. Next, the block was precrushed to partlculate material with a size of less than 150 mm and a quantity of lime (particles 8 to 60 mm) necessary to produce an average CaO-content of 90 weight~
wa~ poured o~er the precrushed material. After this had been done, the whole was ground at a t~mperature higher than 100 C with exclusion of moisture to particulate material with a size of less than 100 microns, a~d the pulverulent product was cooled to room temperature with exclusion of moistureO
The product so made was used as a desulfurizing agent and found to produce the same results (based on its calcium carbide content) as the product u~ed in Example 1.
It is generally accepted that crude iron and steel melt~ can be desulfurized with the use of calcium carbide (briefly termed carbide hereinafter) containing calcium oxide ~brie~ly termed lime herein~
after); c~. German Patents 1 160 457 and 20 37 758 .
In preparing these desulfurizing agents, it has heretofore been customary to admix a liquid carbide melt with a quantity of fine particulate lime necessary to have a homogeneous mixture in the melt.
Next, the whole is allowed to cool, and crushed.
More specifically, it has heretofore been oustomary, to introduce fine particulate lime mto the jet of carbide tapped off from the furnaoe~ Despite the fact that a carbide melt can be admixed with a limited quan~ity of lime only and that liquid carbide is hazardous to handle, the method just described has long been held in the art to be irreplaceable~ Nore particularly, a CaC2/CaO-mixture prepared in the melt has long beer held to be ideally suitable for use in the desulf~rization o~ metal melts~
The preser.t ~nver,tion now unexpectedly provides a process for making a highly efficient agent for de-sulfurizing crude lron and steel melts, which avoids the adverse effects encountered with the methods described heretofore and which comprises: thermally producing, fm m lime and coke, a calcium carbide/cal-cium oxide/starting melt mixture with a CaO-content within the range 20 to 80 weight%; allowing the starting melt mixture to solidify to a block; allow-ing the solidified block to assume an average temperature of more than 400 C, preferably a temperature between 400 C and the solidification point of the ~elt, and precrushing it at that te~perature to particulate ~aterial with a size of less than 150 mm; admlxing the hot crushed material of at least 400 C with a quantity of CaO necessary to have in the resulting mix-ture an o~erall oontent of CaO corresponding to that desired for the finalpro~uct, preferably a CaO-content of more than 45 up to 90 weight%;
thoroughly mixing and crushing the whole with exclusion of moisture a~
temperatures higher than 100 C to particulate material with a size of less than 10 millimeter, preferably less than 10 mierons and ccoling the ground pulverulent material, with exclusion o moisture.
It is good praetiee to use as the caleium carbide/ealeium oxide/
starting melt mixture one which eontains 20 to 45 weight~ of CaO and has been prepared thermally in customary manner, f.rom lime and coke. It .is also possible, however, by admixing a calcium carbide melt ha~ing up to 45 weight% of calcium oxide therein with fine particulate calcium oxide so as to establish a CaC-content of up to 80 weigh~% initially to produoe a calcium carbide/calcium oxide starting melt mixture which is allowed to solidi~y to give a block and the latter is precrus~ed at temperatures higher than 400 C.
The pre~ent invention avoids the need to mix lime with a carbide melt and the di~iculties which are associated with this. Further technically beneficial e~fect~ reside in the following: the carbide melt can be produced without the need to use a specifically composed burden in each particular case or to grind lime to a given particle si~e. In3tead of this, u~e can be made in the present process of a carbide block of which the CaC2 :
CaO-ratio by weight may vary within very wide limi~s?
i. e. which may practically be selected at will; also, use can be made of coarse particulate material with a ~iæe of 8 to 60 mm, for example.
EXAMPLE 1:
A melt with a Cae2-content of 80 weight% and a CaO-content o~ 20 weight% as customarily used in the-prod~ction of comme~ial carbide was placed in a crucible and allowed to cool therein to a carbide block o~ analogous composition.
Once the block was found to have cooled down to an average temperature o~ about 600 C, it was precrushed to particulate material with a ~7e o~ less than 150 mm.
Next~ the hot carbide of 500 C was covered with a quantity o~ lime (in the ~orm of partlcles with a si7-e of 8 to 60 mm) necessary to obtain a mixture wi~h an overall CaO-conten~
o~ 50 wei~h~g6.
Next, the mix*ure was ground at 100 C with exclusion ~ 6 5 of moisture to particles with a size of up to 100 microns and the ground product was cooled to room temperature, with exclusion of moisture.
1500 kg of the product so made was used for de-sulfurizing 300 000 kg of a crude iron melt in customarymanner~ of which the sulfur content initially o~ 0.03 weight% was reduced down to le~s than 0.005 weight%.
EXAMPLE 2:
Calci~ carbide wa~ produced thermally in customary manner, from lime and coke. The furnace burden contained the lime/coke-mix~ure in a ratio by weight of about 110 : 40. This corresponded to carbide containing about 45 weight% of CaO.
Introduced into the jet o~ liquid carbide tapped of~ was CaO int the ~orm of parti.cles with a size o~ 3 to 8 mm, which was used in a qua~Ltity necessary to have an average CaO-colltent of about 80 weight% in the crucible (about 1.2 to 1.3 metric tons o~ C~O per ton o~ material tapped of~).
The material in the crucible was allowed to cool down to an average temperature of not les~ than 600 C
which was the case a~ter 4 hour~. Next, the block was precrushed to partlculate material with a size of less than 150 mm and a quantity of lime (particles 8 to 60 mm) necessary to produce an average CaO-content of 90 weight~
wa~ poured o~er the precrushed material. After this had been done, the whole was ground at a t~mperature higher than 100 C with exclusion of moisture to particulate material with a size of less than 100 microns, a~d the pulverulent product was cooled to room temperature with exclusion of moistureO
The product so made was used as a desulfurizing agent and found to produce the same results (based on its calcium carbide content) as the product u~ed in Example 1.
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for making an agent for desulfurizing crude iron and steel melts the desulfurizing agent being based on calcium carbide contain-ing calcium oxide, which comprises: producing, from lime and coke, a cal-cium carbide/calcium oxide/starting melt mixture with a CaO-content within the range 20 to 80 weight%; allowing the starting melt mixture to solidify to a block; allowing the solidified block to assume an average temperature of more than 400° C and precrushing it at that temperature to particulate material with a size of less than 150 mm; admixing the hot crushed material of at least 400 C with a quantity of calcium oxide necessary to have in the resulting mixture an overall content of CaO corresponding to that desired for the final product; thoroughly mixing and crushing the whole with exclu-sion of moisture at temperatures higher than 100° C to particulate material with a size of less than 10 millimeter; and cooling the ground pulverulent material, with exclusion of moisture.
2. The process as claimed in claim 1, wherein the precrushed block has coarse particulate CaO with a size of 8 to 60 mm poured over it.
3. The process as claimed in claim 1, wherein the precrushed block has a quantity of CaO poured over it which is necessary for the resulting mixture to contain 45 to 90 weight% of CaO.
4) The process as claimed in claim 1, wherein the solidified starting melt mixture is precrushed at temperatures lying between 400° C and the solidification temperature of that mixture.
5) The process as claimed in claim 1, wherein the calcium carbide/calcium oxide-starting melt mixture containing 20 to 45 weight% of CaO is one which has been produced thermally in customary manner from lime and coke.
6) The process as claimed in claim 1, wherein the calcium carbide/calcium oxide-starting melt mixture containing more than 45 up to 80 weight% of CaO is produced by admixing a calcium carbide melt having up to 45 weight% of calcium oxide therein with lime particulate calcium oxide so as to establish a CaO-content of at most 80 weight%
and allowing the whole to solidify to a block.
and allowing the whole to solidify to a block.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19792920353 DE2920353A1 (en) | 1979-05-19 | 1979-05-19 | METHOD FOR THE PRODUCTION OF DEHANIZING AGENTS FOR CRUDE IRON OR STEEL MELT |
| DEP2920353.0 | 1979-05-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1141965A true CA1141965A (en) | 1983-03-01 |
Family
ID=6071196
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000350242A Expired CA1141965A (en) | 1979-05-19 | 1980-04-21 | Production of agent for desulfurizing crude iron and steel melts |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US4318822A (en) |
| EP (1) | EP0019086B1 (en) |
| JP (1) | JPS55154519A (en) |
| AT (1) | ATE2092T1 (en) |
| CA (1) | CA1141965A (en) |
| DE (2) | DE2920353A1 (en) |
| ES (1) | ES8101120A1 (en) |
| NO (1) | NO151971C (en) |
| ZA (1) | ZA802943B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2952686A1 (en) * | 1979-12-29 | 1981-07-02 | Hoechst Ag, 6230 Frankfurt | METHOD FOR THE PRODUCTION OF DESULFURING AGENTS FOR BOD IRON OR STEEL MELT |
| DE3111510A1 (en) * | 1981-03-24 | 1982-10-07 | Hoechst Ag, 6000 Frankfurt | DESULFURATION MIXTURE AND METHOD FOR THE PRODUCTION THEREOF |
| DE3111509A1 (en) * | 1981-03-24 | 1982-10-07 | Hoechst Ag, 6000 Frankfurt | METHOD FOR THE PRODUCTION OF DESULFURING AGENTS FOR BOD IRON OR STEEL MELT |
| DE3535280A1 (en) * | 1985-10-03 | 1987-04-09 | Hoechst Ag | DESULFURATION MIXTURE FOR METAL MELTS, A METHOD FOR THE PRODUCTION THEREOF AND ITS USE |
| US5002733A (en) * | 1989-07-26 | 1991-03-26 | American Alloys, Inc. | Silicon alloys containing calcium and method of making same |
| US5397379A (en) * | 1993-09-22 | 1995-03-14 | Oglebay Norton Company | Process and additive for the ladle refining of steel |
| US6179895B1 (en) | 1996-12-11 | 2001-01-30 | Performix Technologies, Ltd. | Basic tundish flux composition for steelmaking processes |
| CN107344188A (en) * | 2017-07-28 | 2017-11-14 | 靖西天桂铝业有限公司 | Bauxite washing tail mud dry treatment and comprehensive utilization new technology |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT264560B (en) * | 1966-08-25 | 1968-09-10 | Gustav Dipl Ing Wolfram | Basic steelmaking process |
| DE1919414B2 (en) * | 1969-04-17 | 1977-07-14 | Hoechst Ag, 6000 Frankfurt | METHOD AND DEVICE FOR COOLING CALCIUM CARBIDE PICKED IN VESSELS |
| DE1935567B2 (en) * | 1969-07-12 | 1971-05-13 | Knapsack AG, 5033 Hurth Knapsack | PROCESS FOR THE PRODUCTION OF CALCIUM CARBIDE OF CERTAIN QUALITY |
| DE2037758C3 (en) * | 1970-07-30 | 1979-08-02 | Hoechst Ag, 6000 Frankfurt | Process for the production of calcium carbide for the desulfurization of metal melts |
| DE2326539C3 (en) * | 1973-05-24 | 1975-11-13 | Sueddeutsche Kalkstickstoff-Werke Ag, 8223 Trostberg | Process for the production of a desulphurisation mixture for iron melts from calcium carbide and at least one water-containing substance |
| FR2290240A1 (en) * | 1974-11-06 | 1976-06-04 | Unibra Sa | IMPROVEMENTS IN GAS DESULFURATION |
| DE2919324A1 (en) * | 1979-05-14 | 1980-12-04 | Hoechst Ag | DEHANIZER FOR RAW IRON AND STEEL MELTING AND A METHOD FOR THE PRODUCTION THEREOF |
-
1979
- 1979-05-19 DE DE19792920353 patent/DE2920353A1/en not_active Withdrawn
-
1980
- 1980-04-14 EP EP80101984A patent/EP0019086B1/en not_active Expired
- 1980-04-14 AT AT80101984T patent/ATE2092T1/en not_active IP Right Cessation
- 1980-04-14 DE DE8080101984T patent/DE3061404D1/en not_active Expired
- 1980-04-21 CA CA000350242A patent/CA1141965A/en not_active Expired
- 1980-05-09 ES ES491355A patent/ES8101120A1/en not_active Expired
- 1980-05-14 US US06/149,745 patent/US4318822A/en not_active Expired - Lifetime
- 1980-05-16 ZA ZA00802943A patent/ZA802943B/en unknown
- 1980-05-16 NO NO801468A patent/NO151971C/en unknown
- 1980-05-19 JP JP6545180A patent/JPS55154519A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| EP0019086A2 (en) | 1980-11-26 |
| ZA802943B (en) | 1981-06-24 |
| NO151971B (en) | 1985-04-01 |
| DE3061404D1 (en) | 1983-01-27 |
| JPS55154519A (en) | 1980-12-02 |
| ES491355A0 (en) | 1980-12-16 |
| EP0019086A3 (en) | 1981-04-01 |
| DE2920353A1 (en) | 1980-11-27 |
| US4318822A (en) | 1982-03-09 |
| NO151971C (en) | 1985-07-10 |
| EP0019086B1 (en) | 1982-12-22 |
| ATE2092T1 (en) | 1983-01-15 |
| JPS6353245B2 (en) | 1988-10-21 |
| NO801468L (en) | 1980-11-20 |
| ES8101120A1 (en) | 1980-12-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |